The accompanying post describes the requested behavior as painting the image rapidly, in a few seconds, with a simulated paintbrush.
Willison says the artifact was built from a prompt to Claude Opus 5.5 High. The tool uses Sobel edge detection and, according to the post, has no external libraries beyond Google Fonts. The post includes an example described as a simulated oil painting of a heron photograph.
Quick Study follows an earlier watercolor experiment by Willison using Claude Fable and P5.js. The source does not provide benchmark results, image-quality comparisons, supported file formats, browser requirements, licensing terms, or evidence that the technique is suitable for production image-editing workflows.